diff --git a/README.md b/README.md index e69de29bb2d1d6434b8b29ae775ad8c2e48c5391..361179e420fbad4abb88f951d8422f0ee62f53db 100644 --- a/README.md +++ b/README.md @@ -0,0 +1,53 @@ +# Short description +Fortran program to simulate beta-delayed particle emission. + +# Detailed description +A detailed description can be found [here](https://git.kern.phys.au.dk/oliskir/bedepe/blob/master/description.pdf). + +# Files +- Simulation program: [bedepe.f](https://git.kern.phys.au.dk/oliskir/bedepe/blob/master/bedepe.f) +- Example input file: [input0](https://git.kern.phys.au.dk/oliskir/bedepe/blob/master/input0) +- Program that calculates ξ and Θ: [spincoeff.f](https://git.kern.phys.au.dk/oliskir/bedepe/blob/master/spincoeff.f) + +# Compile +First you must install CERNLIB. In Ubuntu this is easily accomplished with the command sudo apt-get install cernlib. +Bedepe may then be compiled with the command gfortran bedepe.out bedepe.f -static -lpacklib -lkernlib -lmathlib. +This creates the executable file bedepe.out. + +# Output and input +The program simulates beta-delayed particle emission (neutron, proton, alpha). The output file (bedepe.dat) has seven columns with the following information: +1. Event number +2. Kinetic energy of beta +3. Kinetic energy of delayed particle +4. Kinetic energy of final nucleus +5. Angle between beta and delayed particle +6. Angle between delayed particle and final nucleus +7. Weight of event + +Quantities are measured in the rest frame of the decaying nucleus. Angles are in degrees and energies are in keV. The maximum weight assigned to any event is given at the end of the output file. + +The program also produced a histogram file (bedepe.his), which can be viewed in PAW, with the following histograms: +- Histogram #10: Recoil energy +- Histograms #11-15: Column 2-6 as defined above + +The following information must be provided in the input file (input0): +1. Number of events +2. Q-value +3. Particle-decay threshold in daughter nucleus +4. Excitation energy in daughter nucleus +5. Mass number of initial nucleus +6. Particle emission (0=neutron, 1=proton, 2=alpha) +7. a3 +8. ξ +9. Θ + +The example input file is for simulating beta-delayed alpha emission from 8B assuming 3.0 MeV excitation energy in 8Be. a3 is the so-called triple-correlation coefficient which equals -1 for pure Gamow-Teller decays, +1 for pure Fermi decays and takes on values between -1 and +1 for mixed decays. ξ and Θ are spin-dependent coefficients given by the these formulas. + +# Comments +Feel free to contact me with questions or comments. Already now, I can point to one way in which the simulation program may be improved, namely, by including Coulomb effects in the beta phase-space function. +Also, it would be very useful if one could simulate a distribution of excitation energies in the daughter nucleus, specified by an analytic function or a histogram. +Finally, the program should be rewritten in C++ and linked to ROOT libraries instead of PAW. + +# References +- E. T. H. Clifford et al., Nucl. Phys. A 493, 293 (1989). +- B. R. Holstein, Rev. Mod. Phys. 46, 789 (1974). \ No newline at end of file